To get a 75, yes, that's luck. Many people aim for a 75 and get a 75, but it's risky business. So luck is a big factor there. But to do well on the exam (i.e. get higher than an 80), it's all based on how well you studied. When someone gets a 95 on FAR, I hardly think it's luck. I think they just really know their stuff.
Also, I do not think it's a great idea to study the morning of your exam. Take it easy and a relax. Save the stress until your exam time. You've stressed yourself enough over the past month or so trying to prepare. Always relax the day before and the morning of your exam. This is not the kind of exam where you can cram last minute studying. It can make things worse instead of better.